Rain is liquid water in the form of droplets that have condensed from atmospheric vapor and then become heavy enough to fall under gravity. In mountainous areas, precipitation is possible where upslope flow is maximized within windward sides terrain at elevation which forces moist air to condense rainfall. Weather sky atmosphere nimbus wet falls rains overcast approaching storm stormy dark gray depressing gloomy dreary cumulonimbus stratus nimbostratus microburst hurricane typhoon thunderstorm tornado supercell downburst squall rainy raining downfall barren arid vegetation infertile xeric desertic treeless dried dry drought dehydrated waterless steppe unspoiled nobody gobi kyzylkum taklamakan karakum desert UHD 4K 3840X2160.